Due to continued increases in the price of petroleum-based fuels, and concerns about by-products of burning petroleum-based fuels, electric and hybrid cars have become more popular with purchasers and more economical as well.
An electric car is a type of alternative fuel vehicle that utilizes an electric motor and motor controller instead of an internal combustion engine. A hybrid car is a type of alternative fuel car that includes both an electric motor or motors and an internal combustion engine. Currently, in most cases, electrical power is stored and derived from battery packs carried on board the vehicle. Fuel cells are also being used to power electrical motors.
In a pure electric vehicle, with no corresponding internal combustion engine, an electric engine replaces the internal combustion engine, providing a central power plant to provide power to a mechanical distribution system (a transmission) that then transfers the power to disparately placed wheels.
A similar system is used in hybrid vehicles, with the exception that both an electric motor and an internal combustion motor (albeit smaller than an internal combustion motor for an internal combustion-only vehicle) work together to perform the function of the traditional internal combustion motor. As in the case of the pure electric vehicle, a mechanical distribution system is utilized to transfer power from the centralized motor compartment to the disparate positions of the wheels.
In a conventional electric motor centralized at an engine compartment, the outer casing (the stator) is stationary while a rotating portion inside the stator (the rotor) rotates to generate mechanical energy. The transmission of the mechanical energy from the electrical engine in the centrally placed engine compartment of the vehicle to remote load locations at the wheels introduces losses into the system that reduce the efficiency of the electrical vehicle, and thereby decreases the overall range of an electrical vehicle.
Accordingly, advances in electric vehicle design are needed to further improve energy efficiency and reduce manufacturing and/or total ownership costs so as to increase the availability of electric and hybrid vehicles to consumers around the world.